Bellows pump



June 28, 1966 A. G. M CORMICK 3,257,952

BELLOWS PUMP Filed June 29, 1964 FIG. 3

II I

lltll \Lll INVENTOR. ALAN G. MCCORMICK HIS ATTORNEY United States Patent 3,257,952 BELLOWS PUMP Alan G. McCormick, 1408 Laird Ave.,

' Salt Lake City, Utah Filed June 29, 1964, Ser. No. 378,542 11 Claims. (Cl. 103-38) The present invention relates to bellows pumps, and more particularly, to a new and improved bellows pump which may be extremely accurately metered by suitable adjustment means.

Accordingly, a principal object of the present invention is to provide a new and improved bellows pump pump having a micrometer adjustment designed to control volumetric displacement of the pump.

A further object is to provide in a bellows pump a shunting chamber which is of such an adjustable nature as to permit the shunting of operating fluid during pressure strokes of the pump, so as to reduce or enlarge, by desired increments or continuously, the expansion of the pump bellows during its operative cycle.

A further object is to provide a controlled shunting chamber in a bellows pump which is of a nature as to permit internal displacements of the operating fluid of the pump in a controlled manner so as to meter accurately the volumetric'output of the pump for any particular cyclical operation thereof.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:

FIGURE 1 is a side elevation, partially broken away and sectioned for convenience of illustration, of a new and improved pump, with its metering means, incorporating th principles of the present invention.

FIGURE 2 is an end view in reduced scale of the pump structure of FIGURE 1, this illustrating the manner in which the main portion of the pump is or may be mounted to external structure.

FIGURE 3 is an enlarged, fragmentary side elevation of the central portion of an optional embodiment of the invention, incorporating alterative metering means for the pump.

FIGURE 4 is an enlarged, fragmentary side elevation of the upper portion of the structure of FIGURE 3 wherein this embodiment of the invention is slightly modified.

FIGURE 5 is a fragmentary, schematic detail illustrating that the fine adjustment metering control of the pump can be directly connected to the pump bellows chamber when corrosive, pumped liquids are not involved.

In FIGURES l and 2 base plate is welded or otherwise secured to the bottom flanges l1 and 12 of I-beams 13 and 14, respectively. Cross braces 15 and 16 may be disposed between and secured to the two I-beams 13 and 14, if desired. Brackets 17 and 18 are secured by means of attachments 19 and 20 to the pair of I-beams 13 and 14, and are shown specifically in FIGURE 2. Stud attachments 21 and 22 are securely threaded into or are otherwise afiixed to housing structure 23 of the bellows pump 24. The studs 21 and 22 are cooperatively disposed within suitable apertures A, either tapped or of other condition, which provide for the secure mounting of the pump between brackets 17 and 18.

not only with mounting boss 44 but also with piston ice In turning now to the working components of the bellows pump 24, it will be seen that the housing structure 23 includes a flanged chamber member 25 having peripheral flange 26. Chamber member 25 includes inlet and outlet ports 27 and 28 also an internal chamber wall 29 which is proximately disposed with respect to and yet spaced from outer surface 30 ofexpandable and contractabl bellows 31. A reservoir member 32 is shown to include a flange 33 which, by means of attachments 34 through respective apertures B, provide interconnection between flange 33 and flange 26 of the reservoir member 32 and chamber member 25, respectively.

The reservoir member includes or is as otherwise integral with-or fixedly disposed with respect to the cylinder 36. The same may include a drain and air bleeder plug 37 provided with O-ring seal 38 disposed in the groove 39 of cylinder 36. Piston 40 or the wall of cylinder 36 includes a peripheral groove 41 which is provided for piston sealing ring 42. The piston 40 is suitably relieved at 43 to provide room for mounting boss 44, mounted about piston 45, of the actuating rod. The latter is integral rod yoke-half 47. The remaining yoke-half 48 is secured to the yoke-half 47 by means of conventional cap screws 49. The combined yoke 50, comprised of yoke halves 48 and 49, centrally includes a bearing 51 which rides about bushing 52. Disposed inwardly of bushing 52 and adjustably mounted on shaft 54 is eccentric split bushing53 which, through rotational displacement adjustment, determines the length of stroke of piston 40.

Shaft 54 is journaled in pillowblock bearings 55 which in turn are mounted by means of attachments 56 to the upper portions of I-beams 13 and 14. Stroke indicator 57 may likewise be provided, and is axially disposed with respect to shaft 54, and is fixed or rotatable on shaft 54, for indicating selected length of stroke and, consequently, coarse adjustment for volumetric displacement of the pump. Of special importance is the inclusion of auxiliary chamber structure 58, including a chamber member 59 mounted by bolt attachments 60 to the housing structure 23 and, in particular, the reservoir member 32 thereof. Cooperating bores 61 and 62 of the reservoir member 32 and auxiliary chamber structure 58 provide inter-communication between reservoir 63 and the interior 64, of chamber structure 58. Chamber member 59 is interiorly threaded at 65 to receive threaded plug P and the threaded shank 66 of adjustment screw 67. Chamber 64 may be suitably filled with a pressurized gas or even a spring 69 to back the otherwise free-floating piston 70, the latter being provided with sealing means 71. It will be noted that the possible travel length of piston 70 is determined by the adjustment of adjustment screw 67 relative to its longitudinal disposition within chamber 64.

Final details of the structure include a chamfered bore 72 within the head portion 73 of cylinder 36, this to'provide a tapered admittanc for O-ring 42. Also, it will be noted that the pump bellows 31 includes a flange 30 which provides a gasket securement between flanges 26 and 33, and retentive securement of the pump bellows by the latter. Transverse O-ring seals 77 and 78 may be provided as needed. Also, air bleed aperture will genso as to produce the reciprocating movement of pin 45 and hence of piston 40. Fluid media 80 such as simply a hydraulic liquid (or even a gaseous medium) is included within the reservoir area of the pump as indicated at 80.-

Fluid pressure is always equalized in both sides of bellows 30. During pressure strokes the piston 40 is urged 3 to the left in FIGURE 1 toward the pump bellows 31, causing the latter to expand. Suitable check valves (not shown) are conventionally included in the respective lines connected to bleeder aperture A, the inlet port 27, and outlet port 28. As the pump bellows expands within the chamber, the pressure created thereby [forces outwardly the displaced liquid through valved outlet port 28.

During the return stroke of the piston the bellows tends to return to its nominal configuration so that additional fluid is introduced through inlet port 27.

Of special importance, again, is the inclusion of the auxiliary chamber structure 58. It will cleanly be seen that the adjustment of the adjustment screw 67 will control the effective height of the interior chamber of structure 58 and hence the amount of fluid that can be shunted into this chamber during the intervals of the expansion of the bellows as produced by the downstrokes of piston 40. Chamber structure 58, hence, serves to meter the volume output of the pump. The less adjustment screw 67 protrudes in chamber 64, the greater will be the shunting effect of hydraulic fluid therein upon pressure strokes of piston 40, the less the expansion of bellows 31, and the less the output of the pump. It will be understood that the spring constant of spring 69, or the pressure of the air backing piston 70, will be sufficient to permit the piston to return to its most downwardly position as indicated in FIGURE 1 on the return strokes of piston 40, this to return hydraulic fluid or other media to the reservoir and permit the same metering action on subsequent downward strokes.

Thus, during pressure strokes the piston 70 will leave its most downwardly position and travel upwardly to be stopped by the end extremity 86 of adjustment means 67. A Teflon washer maybe included, or other suitable means of course, to reduce chatter effect or noise. Again, the fluid media is returned to the reservoir upon upstrokes because of reduced pressure on the fluid media and the spring constant of the spring 69 (or the air pressure used).

In summary, auxiliary chamber structure 58 provides a way of shunting a portion of the hydraulic fluid or other fluid media from the reservoir 63, this with an automatic return piston which is selectively withdrawable, during pressure strokes of the piston, for admitting a given amount of fluid. The amount of fluid admitted controls the amount of fluid exhausted through the external pumping circuit. The higher the adjustment screw 67 is screwed upwardly, the greater the auxiliary chamber and the smaller the volume of fluid pumped through outlet orifice 28. Where, however, the adjustment screw 67 is progressively threaded into the chamber as indicated in FIGURE 1, then little if any fluid is shunted away from the expandable bellows 31 during pressure strokes of the piston, :50 that the volume displaced by the pump Will be greatest.

The embodiment of the invention shown in FIGURES 1 and 2 illustrate the free-floating piston concept associated with piston 70 of the invention.

In FIGURE 3 is indicated another embodiment in which a somewhat different auxiliary structure is utilized for accomodating shunting displacement of the hydraulic media used. The housing structure 23 in the embodiment shown in FIGURE 3, is substantially indentical to housing stnucture 23 in FIGURE 1, except for the following limitations which are now enumerated. Auxiliary structure 100 includes an auxiliary cylinder 101 provided with a flange 102, the latter secured by attachments 103 to structure 23. The knurled head 104 of adjustment means 105 includes a shaft 106 fixedly connected to adjustment piston 107. The piston 107 having apertures B is adjustable within threaded plug P to assume any given height orientation in chamber 108. Reservoir 109 includes an expandible diaphragm 110 peripherally secured in place as shown and situated over perforated wall region 111 having perforations or bores 111', and is disposed in communication with pneumaticor hydraulic source 112.

In operation, the increased pressure of hydraulic fluid during the pressure strokes of piston 40 expands the diaphragm 110 outwardly into the cavity of cylinder 101 and that such expansion is delimited by the position of stop means or piston 107, which position is adjustable. During return strokes of piston 40, then gaseous source S, in communicating with perforations or bores B of piston 107, will urge the diaphragm back against the reservoir portion of the structure at region 111. Accordingly,'the positioning of piston 107 within cylinder 101 determines the shunting effect of the fine adjustment metering structure and hence the volumetric output of the pump.

It is to be noted that any given adjustment of the adjustment means fixes the volume area of chamber portion 117, and hence, the maximum displacement of diaphragm within chamber 117 of auxiliary cylinder 101.

In FIGURE 4 is illustrated an enlarged portion of the upper structure of structure 23 in FIGURE 3 wherein the same has been slightly modified. In the FIGURE 4 modification, the gaseous source S is coupled by line 120, slip coupling 121 and line 122 to the manually adjustable knurled head 123, keyed to threaded shank 124 of piston 125. The piston is hollow at 126, and the hollow area 126 communicates with gaseous source S. The downward face 127 is provided with a perforated insert 128 having apertures 129 which offer communication to diaphragm 110. Diaphragm 110, again, is of rubber or Neoprene and is readily expandable into and contractable from the chamber 131 of auxiliary cylinder 132. Auxiliary cylinder 132 includes a threaded mount 133 for receiving the shank 124 of the piston 125. Attachments 134 secure the auxiliary cylinder construction to structure 23 and, in particular, to reservoir member 32. This time the reservoir member 32' includes not only aperture 62 but also a shoulder 136 receiving perforated screen insert 137. Accordingly, it will be seen that pressure surges as caused by the downstrokes of piston 40 (see FIGURE 3) will produce a shunting, through the perforations of insert 137, to expand diaphragm 110 in FIGURE 4 upwardly toward the head or face of piston 125, thus admitting fluid or liquid into the chamber area 131 in much the same manner as in connection with chamber area 117 of the embodiment of FIGURE 3. The piston is appropriately sealed by O-ring 138, this serving to retain a pressure of gaseous source S against the upper surface of diaphragm 110. Adjustment of head 123 controls the height of the piston face above diaphragm 110 and hence the amount of expansion of diaphragm 110 which is permitted. During return strokes of piston 40 of the structure, the gaseous pressure of source S in FIGURE 4 overcomes the pressure of the hydraulic fluid in reservoir 23 so as to return the diaphragm back to its nominal condition, shown in solid lines in FIGURE 4, which returns the hydraulic fluid to the central portion of the re servoir. As before explained in connection with the embodiment of FIGURE 3, this affects the controlled metering of the output of the pump.

' FIGURE 5 illustrates that whatever form the metering adjustment structure may take, ie that shown in FIG- URES 1, 3, and 4, for example, the same metering adjustment M may be aflixed over aperture A, whether a single' aperture or many drilled holes through the wall of structure 23 (or 23), so that in fact the metering adjustment may be operatively disposed either with the reservoir, as shown in FIGURES 14, or even with the bellows chamber C associated with bellows chamber member 25. In the case of corrosive liquids, of course, then an indirect metering control is needed in which case the metering adjustment means of FIGURES 1-4 will be operatively associated with the hydraulic fluid within the reservoir of the pump. Where, however, no corrosive liquid problem is present, then the metering adjustment means M, of whatever form as illustrated in FIGURES 1-4, may be disposed for operative communication with the pump fluid, i.e. with bellows chamber C.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim:

1. In bellows pump including, in combination, housing structure defining a bellows chamber having a chamber wall provided with inlet and outlet ports, a cylinder, and a reservoir disposed between and interconnecting said bellows chamber and said cylinder; a pump bellows disposed within said bellows chamber and spaced from said chamber wall thereof, said pump bellows opening toward said reservoir; means for sealing said reservoir from that portion of said bellows chamber between said bellows chamber wall and the exterior of said pump bellows; a piston reciprocatively and operatively movable within said cylinder; means for reciprocatively driving said piston; and operating fluid operatively disposed in said housing structure within said bellows and between said bellows and said piston; and improvement comprising means fix- 4 edly disposed with respect to said housing structure and communicating with said reservoir for receiving a given quantity of said operating fluid within said reservoir during piston travel toward said pump bellows and for reintroducing said operating fluid into said reservoir during piston travel away from said pump bellows, and adjustable means .cooperable with said receiving means for regulating the maximum amount of said operating fluid recovered by said receiving means to vary the flow of said pump.

2. The structure of claim 1 wherein said receiving means comprises an auxiliary cylinder fixedly disposed with respect to and communicating with said reservoir, a free-moving piston operatively disposed within said auxiliary cylinder, fixed means for limiting the travel of said free-moving piston operatively toward said reservoir, pressure means for resiliently urging said free-moving piston toward said travel limiting means, and wherein said regulating means comprises adjustable means operatively connected to and extending within said auxiliary cylinder for adjustably limiting the travel of said free-moving piston operatively away from said reservoir, to admit operating fluid from said reservoir into said auxiliary cylinder.

3. The structure of claim 2 wherein said pressure means comprises a compression spring.

4. The structure of claim 2 wherein said pressure means comprises a gaseous pressure source.

5. The structure of claim 1 wherein said reservoir includes a perforated wall region, said receiving means including an expandible and contractible diaphragm disposed over said perforated wall region, and an auxiliary cylinder mounted over said diaphragm and to said reservoir, sealing the former to the latter, said regulating means including adjustable stop means disposed within said auxiliary cylinder and adjustable longitudinally therewithin for limiting the maximum expansion of said diaphragm within said auxiliary cylinder, and said receiving means including pressure means for returning said diaphragm to its contracted position against said reservoir during return strokes of said piston.

6. Structure according to claim 5 wherein said adjustable stop means comprises an adjustable piston provided with perforations communicating with said diaphragm, said pressure means comprising a source of fluid pressure coupled to said auxiliary cylinder and communicating through said piston perforations to pressure contact said diaphragm.

7. Structure according to claim 5 wherein said adjustable stop means comprises an adjustable piston provided with perforations communicating with said diaphragm, said pressure means comprising a source of fluid pressure coupled to said piston and communicating through said piston perforations to pressure contact said diaphragm.

8. The structure of claim 1 wherein said reservoir has a perforated wall region, said receiving means comprises an outwardly expandible and inwardly contractible diaphragm means disposed over said perforated region, and resilient pressure means backing said diaphragm means for resiliently urging inwardly against reservoir said diaphragm means; and wherein said regulating means comprises an auxiliary cylinder afiixed to said reservoir over said diaphragm means for cyclically receiving the same, and adjustable means secured to and extending within said auxiliary cylinder for adjusting the maximum penetration within said auxiliary cylinder of said diaphragm means during pressure strokes of said piston.

9. In a bellows pump for pumping a pumpable fluid and including, in combination, housing structure defining a bellows chamber having a chamber wall provided with inlet and outlet ports, a cylinder, and a reservoir disposed between and interconnecting said bellows chamber and said cylinder; a pump bellows disposed within said bellows chamber and spaced from said chamber wall thereof, said pump bellows opening toward said reservoir; means for sealing said reservoir from the portion of said bellows chamber between said bellows chamber wall and the exterior of said pump bellows; a piston reciprocatively and operatively movable within said cylinder; means for reciprocati'vely driving said piston; and operating fluid operatively disposed in said housing structure within said bellows and between said bellows and said piston; an improvement comprising means fixedly disposed with respect to said housing structure and communicating with one of said reservoir and said bellows chamber for receiving from the same a given quantity of fluid t-herefrom during piston travel toward said pump bellows and for reintroducing said fluid therein during piston travel away from said pump bellows, and adjustable means cooperable with said receiving means for regulating the maximum amount of fluid recovered by said receiving means.

10. The structure of claim 9 wherein said receiving means communicates with said bellows chamber.

11. The structure of claim 1 wherein said receiving means comprises an auxiliary cylinder fixedly disposed with respect to and communicating with said reservoir, a free-moving piston operatively disposed within said auxiliary cylinder, annular seal means for sealing said piston with respect to said auxiliary cylinder, fixed means for limiting the travel of said free-moving piston operatively toward said reservoir, pressure means for resiliently uging said free-moving piston towad said travel limiting means and wherein said regulating means comprises adjustable means operatively connected to and extending within said auxiliary cylinder for adjustably limiting the travel of said free-moving piston operatively away from said reservoir, to admit operating fluid from said reservoir into said auxiliary cylinder.

References Cited by the Examiner UNITED STATES PATENTS 1,868,498 7/1932 Gruman l0338 X 2,303,597 12/1942 Adelson 10344 2,343,962 3/1944 Dodson l03-44 2,713,827 7/1955 Hoop 103-44 2,856,857 10/1958 Saalfrank 103-44 2,869,467 1/1959 Limpert etal. 103-44 X 3,168,045 2/1965 Sebastiani l0344 ROBERT M. WALKER, Primary Examiner. 

1. IN BELLOWS PUMP INCLUDING, IN COMBINATION, HOUSING STRUCTURE DEFINING A BELLOWS CHAMBER HAVING A CHAMBER WALL PROVIDED WITH INLET AND OUTLET PORTS, A CYLINDER, AND A RESERVOIR DISPOSED BETWEEN AND INTERCONNECTING SAID BELLOWS CHAMBER AND SAID CYLINDER; A PUMP BELLOWS DISPOSED WITHIN SAID BELLOWS CHAMBER AND SPACED FROM SAID CHAMBER WALL THEREOF, SAID PUMP BELLOWS OPENING TOWARD SAID RESERVOIR; MEANS FOR SEALING SAID RESERVOIR FROM THAT PORTION OF SAID BELLOWS CHAMBER BETWEEN SAID BELLOWS CHAMBER WALL AND THE EXTERIOR OF SAID PUMP BELLOWS; A PISTON RECIPROCABLY AND OPERATIVELY MOVABLE WITHIN SAID CYLINDER; MEANS FOR RECIPROCATIVELY DRIVING SAID PISTON; AND OPERATING FLUID OPERATIVELY DISPOSED IN SAID HOUSING STRUCTURE WITHIN SAID BELLOWS AND BETWEEN SAID BELLOWS AND SAID PISTON; AND IMPROVEMENT COMPRISING MEANS FIXEDLY DISPOSED WITH RESPECT TO SAID HOUSING STRUCTURE AND COMMUNICATING WITH SAID RESERVOIR FOR RECEIVING A GIVEN QUANTITY OF SAID OPERATING FLUID WITHIN SAID RESERVOIR DUR- 